package com.ljk.study8httpfunction.httputil;


import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

/**
 * desc: java自带的http方法使用
 *
 * @author ljk
 * @date 2021/3/28 23:31
 */
public class JavaHttpUtils {
    public static final int HTTP_OK = 200;

    public static void main(String[] args) {
        String httpurl = "http://127.0.0.1:8080/h1";
        String getRes = doGet(httpurl);
        String postRes = doPost(httpurl,"");

        System.out.println(getRes);
        System.out.println(postRes);
    }


    /**
     * desc: get方法
     *
     * @param httpurl 地址url
     * @return String
     * @author ljk
     * @date 2021/3/30 23:33
     */
    public static String doGet(String httpurl) {
        HttpURLConnection connection = null;
        // 返回结果字符串
        String result = null;
        try {
            // 创建远程url连接对象
            URL url = new URL(httpurl);
            // 通过远程url连接对象打开一个连接，强转成httpURLConnection类
            connection = (HttpURLConnection) url.openConnection();
            // 设置连接方式：get
            connection.setRequestMethod("GET");
            // 设置连接主机服务器的超时时间：15000毫秒
            connection.setConnectTimeout(15000);
            // 设置读取远程返回的数据时间：60000毫秒
            connection.setReadTimeout(60000);
            // 发送请求
            connection.connect();
            // 通过connection连接，获取输入流
            if (connection.getResponseCode() == HTTP_OK) {
                result = receiveString(connection);
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            connection.disconnect();        // 关闭远程连接
        }
        return result;
    }

    /**
     * desc: post方法调用
     *
     * @param httpUrl 地址url
     * @param param   入参
     * @return String
     * @author ljk
     * @date 2021/3/30 23:34
     */
    public static String doPost(String httpUrl, String param) {

        HttpURLConnection connection = null;
        String result = null;
        try {
            URL url = new URL(httpUrl);
            // 通过远程url连接对象打开连接
            connection = (HttpURLConnection) url.openConnection();
            // 设置连接请求方式
            connection.setRequestMethod("POST");
            // 设置连接主机服务器超时时间：15000毫秒
            connection.setConnectTimeout(15000);
            // 设置读取主机服务器返回数据超时时间：60000毫秒
            connection.setReadTimeout(60000);
            // 默认值为：false，当向远程服务器传送数据/写数据时，需要设置为true
            connection.setDoOutput(true);
            // 默认值为：true，当前向远程服务读取数据时，设置为true，该参数可有可无
            connection.setDoInput(true);
            // 设置传入参数的格式:请求参数应该是 name1=value1&name2=value2 的形式。
            connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            // 设置鉴权信息：Authorization: Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0
            connection.setRequestProperty("Authorization", "Bearer da3efcbf-0845-4fe3-8aba-ee040be542c0");
            sendString(connection, param);
            // 通过连接对象获取一个输入流，向远程读取
            if (connection.getResponseCode() == HTTP_OK) {
                result = receiveString(connection);
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 断开与远程地址url的连接
            connection.disconnect();
        }
        return result;
    }

    /**
     * desc: 接收数据的方法
     *
     * @param connection http连接
     * @return String 返回的String数据
     * @author ljk
     * @date 2021/3/30 23:09
     */
    private static String receiveString(HttpURLConnection connection) throws IOException {
        // 存放数据
        StringBuffer sbf = new StringBuffer();
        try (InputStream is = connection.getInputStream();
             // 封装输入流is，并指定字符集
             BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF-8"));
        ) {
            String temp = null;
            while ((temp = br.readLine()) != null) {
                sbf.append(temp).append("\r\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
            throw e;
        }
        return sbf.toString();
    }

    /**
     * desc: 发送数据的方法
     *
     * @param connection http连接
     * @param param      入参
     * @return String
     * @author ljk
     * @date 2021/3/30 23:09
     */
    private static void sendString(HttpURLConnection connection, String param) throws IOException {
        // 通过连接对象获取一个输出流
        try (OutputStream os = connection.getOutputStream()) {
            // 通过输出流对象将参数写出去/传输出去,它是通过字节数组写出的
            os.write(param.getBytes());
        } catch (IOException e) {
            e.printStackTrace();
            throw e;
        }
    }
}


